Sensory Systems Flashcards

1
Q

How are sensory stimuli received and processed by the body?

A
  1. sensory organs detect a physical or chemical stimulus in the environment
  2. specialized sensory cells detect these signals and code them as information to transmit and process thru the nervous system
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
2
Q

What is sensory transduction?

A

the conversion of physical or chemical stimuli into nerve impulses

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
3
Q

What are mechanoreceptors?

A

sensory receptors that respond to physical deformations of their membrane

touch, stretch, pressure, motion, sound

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

What are hair cells?

A

specialized mechanoreceptor that senses movement and mechanical vibrations

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
4
Q

How do hair cells work?

A
  1. hair cells sense vibrations
  2. vibrations move stereocilia
  3. motion of stereocilia causes depolarization of the cell
  4. neurotransmitters are released
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
5
Q

How do sound waves travel through the ear?

A
  1. sound waves travel into the outer ear
  2. travels thru ear canal and hits the eardrum, causing it to vibrate
  3. the vibration moves the ossicles, which transmit vibration to the oval window in the cochlea
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
6
Q

What occurs in the basal membrane after the oval window is depressed by the ossicles?

A
  1. oval window creates waves that travel thru the cochlear fluid
  2. waves cause the basilar membrane to move
  3. movement of basilar membrane is transmitted into electrical impulses within the Organ of Corti
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
7
Q

What happens to the hair cells when the basilar membrane moves?

A
  1. stereocilia on top of hair cells move against the tectorial membrane
  2. stereocilia bent toward the kinocilium stimulates the opening of K+ channels at the hair cell terminal, leading to depolarization
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
8
Q

When the stereocilia are ____, the hair cell is at rest.

A

straight

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
9
Q

When the stereocilia are bent ____ the kinocilium, the hair cell depolarizes, causing ____.

A

toward the kinocilium; stimulation

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
10
Q

When the stereocilia are bent ____ the kinocilium, the hair cell hyperpolarizes, causing ____.

A

away from; inhibition

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
11
Q

Hair cells at the base of the cochlea transmit ____ frequencies.

A

high

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
12
Q

Hair cells at the apex of the cochlea transmit ____ frequencies.

A

low

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
13
Q

What is the process of auditory transduction at the synapse of the hair cell and auditory nerve?

A
  1. K+ ions flow out of stereocilia and into hair cell, causing depolarization
  2. Depolarization stimulates the opening of Ca+ channels at the terminal
  3. Excitatory neurotransmitters are released into the synaptic cleft
  4. Neurotransmitters bind to ligand-gated ion channels of the afferent auditory nerve
  5. EPSPs are received by the afferent auditory nerve as graded potentials, which fire as action potentials to the brain when threshold is reached
  6. Signal is received by the brain and processed as sound
How well did you know this?
1
Not at all
2
3
4
5
Perfectly
14
Q

What are electromagnetic receptors?

A

Sensory cells that respond to electrical, magnetic, and light stimuli

How well did you know this?
1
Not at all
2
3
4
5
Perfectly
15
Q

What are photoreceptors?

A

light detecting electromagnetic receptors found in the eye

16
Q

What protein converts light energy into electrical signals?

A

opsin

17
Q

What light-absorbing pigment molecule is found in opsin?

A

retinal

18
Q

What is the resting membrane potential of photoreceptor cells?

A

-35 mV

19
Q

Why do photoreceptor cells have a more positive resting membrane potential than neurons?

A

leaky Na+ channels within the photoreceptor cells let in more Na+ ions at rest

20
Q

What are cones?

A

photoreceptor cells in the retina responsible for color vision and greater spatial acuity

21
Q

What are rods?

A

photoreceptor cells in the retina responsible for shades of grey and low light

22
Q

What is glutamate?

A

an excitatory neurotransmitter that sends signals to the brain for visual processing

23
Q

In the dark/light, photoreceptors release glutamate.

A

dark

24
Q

In the dark/light, photoreceptors stop releasing glutamate.

A

light

25
Q

Cis/trans retinal is bound to opsin in the dark.

A

cis

26
Q

Cis/trans retinal is bound to opsin in the light.

A

trans

27
Q

What happens in the photoreceptor cell in the dark?

A
  1. cis retinal is bound to opsin
  2. cGMP activates the opening of Na+ channels
  3. Na+ ions enter the cell, which causes depolarization
  4. glutamate neurotransmitters are released
28
Q

What happens in the photoreceptor cell in the light?

A
  1. light strikes cis retinal, which changes it to trans retinal
  2. trans retinal dissociates from opsin
  3. opsin activates the G-protein transducin, which activates the effector phosphodiesterase
  4. the effector breaks down cGMP back to GMP
  5. lower cGMP concentration closes Na+ channels
  6. cell hyperpolarizes due to Na+ no longer entering the cell
  7. glutamate neurotransmitter release is inhibited
29
Q

In what orde are cells involved in visual processing?

A
  1. cones/rods
  2. bipolar cells
  3. ganglion cells
30
Q

In the light:
Cones/rods are ____, which ____ glutamate release onto the bipolar cell.
Bipolar cells are then ____, which ____ glutamate onto ganglion cells.
Ganglion cells are then ____, which allows it to ____.

A

hyperpolarized; decreases
depolarized; increases
depolarized; send signal to the brain

31
Q

In the dark:
Cones/rods are ____, which ____ glutamate release onto the bipolar cell.
Bipolar cells are then ____, which ____ glutamate onto ganglion cells.
Ganglion cells are then ____, which ____.

A

depolarized; increases
hyperpolarized; reduces
hyperpolarized; prevents signal to the brain

32
Q

You turn on a light so you can get a glass of water. At the moment the light turns ON, the relative amound of G⍺-GDP of trimeric G proteins ____.

A

decreases

when G⍺ is activated, GDP –> GTP

33
Q

If the stereocilia of one hair cell becomes permanently bent away from the kinocilium, what would happen?

A

a single pitch will no longer be perceivable depending on the hair cell’s location